This invention relates to a color image processing apparatus that is suited to color conversion processing. There are various image processing apparatuses that resolve a color character or picture image into red R and cyan C, read them optically, and record the image on a recording paper with an output unit, such as a photoelectric copying machine, according to the read data.
Some of the foregoing image processing apparatuses perform a color conversion function, i.e., processing for converting the part of black characters of a monochromatic document, which is enclosed by a marker, to the color which is the same as a predetermined color.
When the foregoing image processing apparatus performs color conversion, color conversion other than a monochromatic marker, such as red or blue, cannot be performed because reading and recording are performed in red and cyan or red, blue, and black. Therefore the part enclosed by a marker other than red or blue cannot be correctly converted.
There is a color image processing apparatus which resolves a color character or picture image into red R, green G, and blue B, reads them optically, converts them to recording colors yellow Y, magenta M, cyan C, and black B, and records the image on a recording paper with an output unit, such as a photoelectric color copying machine, according to the converted data. The foregoing color image processing apparatus can read and record a color document. However, no consideration is given the full color conversion function of the foregoing apparatus, that is, no consideration is given to the reading of various marker colors or to correcting conversion of black characters to the marker color.